How can all checked items from a list can be fetched?
I need to get all selected (checked) items from the list and populate a vector.
I am not getting all selected items, I am getting only the item on which current focus is.
I am implementing listfield with checkboxes as per the knowledgebase article.
If I use getSelection(), it is returning me the currently highlighted list row index, and not all that have been checked.
As I undestood, sample is How To - Create a ListField with check boxes
Then you can add Vector to the class where ListFieldCallback is implemented:
private Vector _checkedData = new Vector();
public Vector getCheckedItems() {
return _checkedData;
}
and update drawListRow this way:
if (currentRow.isChecked())
{
if( -1 ==_checkedData.indexOf(currentRow))
_checkedData.addElement(currentRow);
rowString.append(Characters.BALLOT_BOX_WITH_CHECK);
}
else
{
if( -1 !=_checkedData.indexOf(currentRow))
_checkedData.removeElement(currentRow);
rowString.append(Characters.BALLOT_BOX);
}
If you would use VerticalFieldManager with custom CheckBoxField, you could iterate over all fields on screen (or any manager) and check if its' checkbox field, then take a value:
class List extends VerticalFieldManager {
...
public Vector getCheckedItems() {
Vector result = new Vector();
for (int i = 0, cnt = getFieldCount(); i < cnt; i++) {
Field field = getField(i);
if (field instanceof CheckboxField) {
CheckboxField checkboxField = (CheckboxField) field;
if (checkboxField.isChecked())
result.addElement(checkboxField);
}
}
return result;
}
}
#sandhya-m
class List extends VerticalFieldManager {
...
public void selectAll() {
for (int i = 0, cnt = getFieldCount(); i < cnt; i++) {
Field field = getField(i);
if (field instanceof CheckboxField) {
CheckboxField checkboxField = (CheckboxField) field;
checkboxField.setChecked(true);
}
}
}
}
Related
In UWP,we can fetch the children by FindDescendants<> .But in winui, we can't able to do that.
By doing with visualhelpertree,It always shows zero count in getchildCount() from the calendarview
I just wanted to know how to fetch the children of calendarview .
Also i have tried this but shows me zero child always,
private void FindDescendants1(DependencyObject parent, Type targetType)
{
int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
itemchange.Text = childrenCount.ToString();
for (int i = 0; i < childrenCount; i++)
{
var child =(CalendarViewDayItem) VisualTreeHelper.GetChild(parent, i);
if (child.GetType() == targetType)
{
results.Add(child);
}
FindDescendants1(child, targetType);
}
}
Simply I have created this function to get the child and called,
foreach (DependencyObject displayedDay in results)
{
//displayedDay = (CalendarViewDayItem)displayedDay;
CalendarViewDayItem c = displayedDay as CalendarViewDayItem;
if (_highlightedDates.Contains(c.Date))
{
Console.WriteLine(c.Date.ToString());
//highlight
c.Background = new SolidColorBrush(Colors.Red);
}
itemchange.Text = c.Date.ToString();
}
But this not getting the child ,results is the list of objects here where it always show me zero .
My first guess is that you are calling FindDescendants1() before the control is loaded, in the constructor for example. If your CalendarView is in a Page, try calling FindDescendants1() in the Page's Loaded event.
But there's another problem in you code below.
var child = (CalendarViewDayItem)VisualTreeHelper.GetChild(parent, i);
You'll get an exception because you're trying to cast every DependencyObject to a CalendarViewDayItem. By removing the cast you should get the CalendarViewItems. Though, I would make the FinDescendants() static and just receive the results:
private static IEnumerable<T> FindDescendantsOfType<T>(DependencyObject parent) where T : DependencyObject
{
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(parent); i++)
{
DependencyObject child = VisualTreeHelper.GetChild(parent, i);
if (child is T hit)
{
yield return hit;
}
foreach (T? grandChild in FindChildrenOfType<T>(child))
{
yield return grandChild;
}
}
}
And use it like this:
this.results = FindChildrenOfType<CalendarViewDayItem>(this.CalendarViewControl);
foreach (var item in this.results)
{
// Do you work here...
}
I have a scenario where i create Entry Controls programmatically.
foreach (var control in FormInfo.FormElementsInfo)
{
case "textbox":
//Some code
break;
case "dropdown":
Entry objDropdown = new Entry();
objDropdown.HeightRequest = 40;
objDropdown.StyleId = Convert.ToString(control.ElementId);
objDropdown.SetBinding(Entry.TextProperty, "ElementValue",BindingMode.TwoWay);
objDropdown.BindingContext = control;
layout.Children.Add(objDropdown);
MessagingCenter.Subscribe<Picklists, string>(objDropdown, "PicklistSelected", (sender, arg) =>
{
objDropdown.Text = arg;
// I tried this too as this is two way binding. It didn't show the value.
//control.ElementValue = arg;
} );
break;
}
If i click on any entry it will open me a list view. Once i select the option in the list view it will populate that data in the Entry.
But this should show the selected value only in the current entry but it is changing the value in all the entry's.
How to avoid this situation. I want the selected value to be populated only in the current entry.
Any suggestion would be appreciated. Thank you.
=== More clear question=====
If we create n number of Entry controls programmatically with 2 way binding . Is it possible to change the single entry value on selecting something in other page? If yes how to achieve this?
FormInfo
public class FormInfo
{
public List<FormsElementInfo> FormElementsInfo { get; set; }
}
FormsElementInfo
public class FormsElementInfo : INotifyPropertyChanged
{
private string _elementValue;
public string ElementValue {
get => _elementValue;
set {
if(_elementValue != value)
{
_elementValue = value;
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("ElementValue"));
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
}
Content Page
public class ListStackOverflow : ContentPage
{
private FormInfo _info = new FormInfo
{
FormElementsInfo = new List<FormsElementInfo>()
{
new FormsElementInfo { ElementValue = "test 1"},
new FormsElementInfo { ElementValue = "test 2"},
new FormsElementInfo { ElementValue = "test 3"},
new FormsElementInfo { ElementValue = "test 4"},
}
};
private StackLayout _stack = new StackLayout();
private List<string> _source = new List<string>
{
"output 1","output 2","output 3","output 4",
};
public ListStackOverflow()
{
//BindingContext = _info;
foreach(var c in _info.FormElementsInfo)
{
Entry tempEntry = new Entry
{
HeightRequest = 40,
Placeholder = c.ElementValue,
BindingContext = c
};
tempEntry.SetBinding(Entry.TextProperty, "ElementValue");
_stack.Children.Add(tempEntry);
}
ListView _lv = new ListView { ItemsSource = _source };
_lv.ItemSelected += Lv_ItemSelected;
_stack.Children.Add(_lv);
Content = _stack;
}
private void Lv_ItemSelected(object sender, SelectedItemChangedEventArgs e)
{
var selectedElement = e.SelectedItem.ToString();
var index = _source.IndexOf(selectedElement);
var entry = _info.FormElementsInfo[index];
entry.ElementValue = selectedElement;
}
}
Output
Selecting the corresponding index in the listview will update "ElementValue" for the same index.
First of all Thank you #Joshua Poling for taking time to help me.
I think MessagingCenter is not suitable for this approach.
I am assigning a unique styleId to each element that i create.That basically stores the position in the stack layout.
I have written a delegate which returns the selected value and also the position of the element. As the element is always an Entry that fires this event. I used the below code to achieve this.
Entry myentry = (Xamarin.Forms.Entry)layout.Children[src.ElementId];
I have problem regarding my Filtering of my Table. I'm using a ViewerFilter and override the select Method to fitler that Table. The Filtertext itself is entered via a Textfield.
So now to my problem. For example my table looks like the following:
column
123
124
In my textfield the user can enter the columnname=data1,data2 to show all rows which have either data1 or data2 as data. so in my above example if the user enters column=123,124 both rows should still be visible. The problem here is that I refresh my tableviewer after each entered character. So when the user enters column=123 the Table only shows one column. When adding ,124 to the filtertext I filter my already filtered table. So no data gets shown at the end. How can I still filter the original Tabledata?
#Override
public boolean select(final Viewer viewer, final Object parentElement, final Object element) {
final String filterString = filterText.getText().toLowerCase();
if (filterString.length() == 0) { return true; }
final mydata myData= (mydata) element;
if (filterString.matches("columnName" + ".+")) {
index = filterString.indexOf("columnName" + ".+");
evaluateText(myData, filterString, i, index + tableColumnsText[i].length())
}
public boolean evaluateText(final mydata data, final String filterText, final int beginningIndex) {
subString = filterText.substring(beginningIndex, filterText.length());
return evaluateString(data.getString(), subString);
}
public boolean evaluateString(final String cellString, final String commaString) {
int countSubstrings = 0;
final String[] items = commaString.split(",");
countSubstrings = items.length;
for (final String s : items) {
if (s.length() != 0) {
if (!cellString.contains(s)) { return false; }
}
}
return true;
}
So I tried to filter out the main components of the method. Can I somehow access the unfiltered table?
I am creating a ListField. in each row of I am adding a image and 3 labelfield.
Can any one tell me how to create a keywordfilterField for this...
Thanks in advance
I am new to blackberry.
Little code will help me alot
This is my code for creating a custom list
class CustomListField extends ListField implements ListFieldCallback
{
String type;
int DISPLAY_WIDTH = Display.getWidth();
int DISPLAY_HEIGHT = Display.getHeight();
Vector mItems = new Vector();
Vector mine = new Vector();
Vector three= new Vector();
// SizedVFM mListManager = new SizedVFM(DISPLAY_WIDTH, DISPLAY_HEIGHT - 40);
Bitmap searchresult = Bitmap.getBitmapResource("res/searchresult.png");
HorizontalFieldManager hfManager;
Bitmap image ,image1;
int z = this.getRowHeight();
CustomListField(String text1,String text2,String type)
{
for (int i = 1; i < 31; i++)
{
mItems.addElement(text1 +String.valueOf(i));
mine.addElement(" "+text2);
three.addElement("31");
}
this.type=type;
this.setRowHeight((2*z));
this.setCallback(this);
this.setSize(20);
//mListManager.add(mListField);
//add(mListManager);
}
public void drawListRow(ListField field, Graphics g, int i, int y, int w)
{
// Draw the text.
image = Bitmap.getBitmapResource("res/searchresult.png");
String text = (String) get(field, i);
String mytext = (String)mine.elementAt(i);
String urtext=(String)three.elementAt(i);
g.drawBitmap(0, y, image.getWidth(),image.getHeight(), image, 0, 0);
g.drawText(text, image.getWidth(), y, 0, w);
g.setColor(Color.GRAY);
g.drawText(mytext, image.getWidth(), y+getFont().getHeight(), 0, w);
g.drawText(urtext,Graphics.getScreenWidth()*7/8,y,0,w);
if (i != 0)
{
g.drawLine(0, y, w, y);
}
}
public Object get(ListField listField, int index)
{
return mItems.elementAt(index);
}
public int getPreferredWidth(ListField listField)
{
return DISPLAY_WIDTH;
}
public int indexOfList(ListField listField, String prefix, int start)
{
return 0;
}
protected boolean touchEvent(TouchEvent message)
{
// If click, process Field changed
if ( message.getEvent() == TouchEvent.CLICK )
{
if(type.equals("Stops"))
UiApplication.getUiApplication().pushScreen(new SearchScreen("Services"));
else if(type.equals("Services"))
UiApplication.getUiApplication().pushScreen(new SearchScreen("Stops"));
return true;
}
return super.touchEvent(message);
}
}
The problem with KeywordFilterField is that it uses internally its own ListField, so I think it is going to be difficult to customize. If you wanted to use it as it is provided, you'll have to use it as follows:
//KeywordFilterField contains a ListField to display and a search edit field to type in the words
KeywordFilterField keywordFilterField = new KeywordFilterField();
//Instantiate the sorted collection:
CustomList cl = new CustomList(mItems);
//Pass the custom collection
keywordFilterField.setSourceList(cl, cl);
//Now you have to add two fields: first the list itself
myManager.add(keywordFilterField);
//And the search field, probably you'd want it at top:
myScreen.setTitle(keywordFilterField.getKeywordField());
You'll have to implement a custom sortable collection to hold the items you wan't to display:
class CustomList extends SortedReadableList implements KeywordProvider {
//In constructor, call super constructor with a comparator of <yourClass>
public CustomList(Vector elements)
{
super(new <yourClass>Comparator()); //pass comparator to sort
loadFrom(elements.elements());
}
//Interface implementation
public String[] getKeywords( Object element )
{
if(element instanceof <yourClass> )
{
return StringUtilities.stringToWords(element.toString());
}
return null;
}
void addElement(Object element)
{
doAdd(element);
}
//...
}
You have a full demo available inside the JDE samples folder. It is called keywordfilterdemo.
To use a custom list like the one you posted, you'll probably have to code a lot of stuff, like a custom EditField to type in the keywords receiving events on every typed character, linked to a search on a sortered collection (maybe you could use a SortedReadableList for this) which will select in your ListField the first search result returned by this collection.
I can't find solution for the following problem. I have custom list field, which overlaps the boundaries of its layout manager. List field consumes navigation events from manager to highlight currently selected row with special color. Layout manager is configured to support scrolling. When I scroll trackwheel down, layout manager invokes scrolling and then passes navigation event to its child, the list field. It results in inproper scrolling, because manager scrolls the whole list down to its bottom hiding list rows on the top including the selected row.
What I want is to ignore scrolling while currently selected list row is still visible and employ it otherwise.
I'm using JDE 4.2.1
Let's say we have ListField implementation:
class LabelListField extends ListField implements ListFieldCallback {
private Vector mValues;
public LabelListField(Vector values) {
super(0);
setRowHeight(getFont().getHeight() + 10);
setCallback(this);
mValues = values;
setSize(mValues.size());
}
public void drawListRow(ListField listField, Graphics g, int index, int y,
int width) {
g.drawText((String) mValues.elementAt(index), 0, y);
}
public Object get(ListField list, int index) {
return mValues.elementAt(index);
}
public int indexOfList(ListField list, String prefix, int start) {
for (int x = start; x < mValues.size(); ++x) {
String value = (String) mValues.elementAt(x);
if (value.startsWith(prefix)) {
return x;
}
}
return -1;
}
public int getPreferredWidth(ListField list) {
return Display.getWidth();
}
}
If we want to align this list within upper and lower fields this way:
ListField with scroll http://img6.imageshack.us/img6/7025/8800j.png
we can limit it's height using custom manager:
class ListManager extends HorizontalFieldManager {
ListField mListField;
public ListManager(ListField listField) {
super(VERTICAL_SCROLL | VERTICAL_SCROLLBAR);
mListField = listField;
add(mListField);
}
public int getPreferredHeight() {
int result = Display.getHeight();
Manager manager = getManager();
if (null != manager) {
for (int i = 0, count = manager.getFieldCount(); i < count; i++) {
if (manager.getField(i) != this)
result -= manager.getField(i).getPreferredHeight();
}
}
// size down to fit max rows without splitting
result = result - result % mListField.getRowHeight();
return result;
}
protected void sublayout(int maxWidth, int maxHeight) {
super.sublayout(maxWidth, maxHeight);
setExtent(maxWidth, getPreferredHeight());
}
}
Now we can use it:
class Scr extends FullScreen implements FieldChangeListener {
LabelField mHeader;
ListManager mHFMList;
HorizontalFieldManager mHFMButton;
LabelListField mListField;
ButtonField mButton;
public Scr() {
super(DEFAULT_MENU | DEFAULT_CLOSE);
mHeader = new LabelField("List Field", FIELD_HCENTER);
add(mHeader);
Vector values = new Vector();
values.addElement("first");
values.addElement("second");
values.addElement("third");
values.addElement("fourth");
values.addElement("fifth");
values.addElement("sixth");
values.addElement("seventh");
values.addElement("eight");
mListField = new LabelListField(values);
mHFMList = new ListManager(mListField);
add(mHFMList);
mHFMButton = new HorizontalFieldManager(FIELD_HCENTER);
add(mHFMButton);
mButton = new ButtonField("Exit", ButtonField.CONSUME_CLICK);
mButton.setChangeListener(this);
mHFMButton.add(mButton);
}
public void fieldChanged(Field field, int context) {
if (mButton == field)
close();
}
}
Tested on eJDE 4.2.1.17 8800
all here's the solution that helped me. By overriding moveFocus in such specific way I managed to modify default behavior of scrolling in layout manager - it skips first items of list field allowing them to stay on top.
public int moveFocus(int amount, int status, int time) {
invalidate(getSelectedIndex());
int unused = super.moveFocus(amount, status, time);
return Math.abs(unused) + 1;
}